Re: 2.6.33.5 rt23: machine lockup (nfs/autofs related?)

[Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>]

On Mon, 2010-07-12 at 20:06 -0700, Fernando Lopez-Lezcano wrote:
> > > --------
> > > BUG: unable to handle kernel NULL pointer dereference at 0000008c
> > > IP: [<c045e50a>] rt_spin_lock_fastunlock.clone.2+0x6/0x3e
> > ...
> > > Pid: 2855, comm: nautilus Not tainted
> > > 2.6.33.6-147.rt23.3.fc12.ccrma.i686.rt #3 P5K/EPU/P5K/EPU
> > > EIP: 0060:[<c045e50a>] EFLAGS: 00210246 CPU: 0
> > > EIP is at rt_spin_lock_fastunlock.clone.2+0x6/0x3e
> > > EAX: 00000078 EBX: ef45393c ECX: 00000000 EDX: 00000078
> > > ESI: ef716edc EDI: 00000000 EBP: f1977c8c ESP: f1977c88
> > >  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 preempt:00000000
> > > Process nautilus (pid: 2855, ti=f1976000 task=f2347130 task.ti=f1976000)
> > > Stack:
> > >  ef45393c f1977c94 c0781206 f1977cc8 c04d842e 00000000 ef703e54 faadd5bc
> > > <0> f1977cdc 126bc87a ef703ddc 00000000 ef45393c ef716edc ef6f5494
> > > faafdc6c
> > > <0> f1977df8 faad9041 c3604b5c faafdc6c ef452bfc 00007e7f f5eb41e8
> > > 00000007
> > > Call Trace:
> > >  [<c0781206>] ? rt_spin_unlock+0x8/0xa
> > >  [<c04d842e>] ? d_materialise_unique+0x210/0x2aa
> > 
> > Can you gdb list *0xc04d842e ?
> 
> (gdb) list *0xc04d842e
> 0xc04d842e is in d_materialise_unique (fs/dcache.c:2073).
> 2068	out_unalias:
> 2069		d_move_locked(alias, dentry);
> 2070		ret = alias;
> 2071	out_err:
> 2072		spin_unlock(&inode->i_lock);
> 2073		if (m2)
> 2074			mutex_unlock(m2);
> 2075		if (m1)
> 2076			mutex_unlock(m1);
> 2077		return ret;
> 
> > Thanks again for all the testing here! Its really appreciated!

I just tried building 2.6.33.6 rt26 (saw it this morning on the site)
and it does not exhibit this problem. Woohoo!

Thanks again!
-- Fernando